Thursday, April 27, 2006

Microwave breast scanner

Researchers from the US National Institutes of Health are working on a safer early-warning system for breast cancer.

The new system would use broadcast frequency radiation instead of X-rays to detect tumours, allowing women to undergo frequent checks without exposure to hazardous ionising radiation.

An array of up to a hundred mini-antennae would be built into a soft, breast-shaped sensing device. Each antenna would emit a very short burst of microwave energy, rapidly scanning across several frequencies, at just one-hundredth of the power output of an ordinary cellphone.

Malignant tissue is far less conductive that normal flesh, and so should reflect much more signal back to detectors built into the same device. Software would remove random reflections from the skin surface and the patent claims that tumours as small as 1 millimetre across would show up using the scanner.

Although the power is low and safe, the signal should be able to penetrate 10 cm of tissue, to reveal deeply hidden menaces. The scan should also take just one-tenth of second.

Red-eye age checker

This could be bad news for under-age drinkers and anyone else trying to lie about their age.

Camera maker Kodak is adapting the technology used to automatically correct flash-induced "red-eye" in digital images to determine a person's age. A patent filed by researchers from the company's labs in Rochester, New York, suggests the technique could provide a quick and easy way to check someone's date of birth.

Red-eye is the effect seen when a person's open pupils allow a camera's flash light to be reflected off their retinas. Red eye correction software analyses a picture, looking for a pair of red dots in the centre of a face, and automatically dulls them to remove the effect.

Kodak's patent mentions previous research suggesting a correlation between age and the way pupils react to light. As a person gets older, their pupils have greater difficulty widening to cope with dim light, it says.

The company suggests that an age-verification system could take mug shots of a person from a set distance in controlled lighting, using a flash. Software would then measure the size of their red-eye dots to determine how wide their pupils are and make an estimate of their age.

Although the patent doesn't say how accurate the system could be it suggests that accuracy could be boosted by automatically looking for wrinkles and grey hair in an image as well. Well, just don't point that thing at me?

Wednesday, April 26, 2006

Apple's all-seeing screen

We could soon see a new kind of display screen from computer maker Apple ? one that simultaneously takes pictures while showing images.

The clever idea is to insert thousands of microscopic image sensors in-between the liquid crystal display cells in the screen. Each sensor captures its own small image, but software stitches these together to create a single, larger picture.

A large LCD screen filled with image sensors would be ideal for videoconferencing, Apple suggests, as participants would always appear to look straight into the "camera". The technique could also add a camera function to a cellphone or PDA without wasting space, and light from the screen should help illuminate a subject.

The more sensors there are, the wider and clearer the image. Sketches accompanying the company's patent show as many sensors as liquid crystal cells in a screen. If some of the sensors have different focal lengths, switching between them would make the screen behave like a zoom lens.

Radio clotting

Major surgery can release a deluge of blood that often flows too fast to clot. If the flow is not staunched in time, this can prevent doctors from seeing what they are doing and may lead to dangerous blood loss.

A team of medics in Wisconsin, working for the US National Institutes of Health, is patenting a drastic solution. A bleeding organ could be "sewn up" by hitting it with a dose of energy along a stitch line, they suggest. The researchers have come up with a tool resembling a hairbrush that has an array of stainless steel "bristles" that serve as tiny electrodes.

To stop blood flowing, or seal off the good parts of an organ before a diseased part is cut away, the tool is pushed onto the tissue so that its electrodes break the surface.

Radio waves, at a frequency of around 10 kilohertz, are then generated by feeding current to the electrodes, with the signals skipping up and down the length of the device for around 5 minutes. This heats the organ tissue along a centimetre-wide track, sealing the blood vessels and preventing further bleeding. The patient would of course be anaesthetised, so they would not feel the procedure.

Friday, April 21, 2006

Micro electrical generator

There is little point in building tiny micro-electro-mechanical devices (MEMS) if they need big batteries to work. So Washington State University, US, has been working on a radical solution ? a microscopic generator that burns hydrocarbon fuel to generate electricity.

Within the device, droplets of fuel are deposited onto a flat metal plate (about 1 millimetre to a side) and then ignited. As the plate heats up, drops of liquid mercury travel along a connected tube to a strip of piezoelectric material. Heat from the mercury causes the piezoelectric strip to flex, generating a small pulse of electric power.

Some of this power is used to create an electrostatic charge which moves the mercury droplets back towards the hot plate to pick up another dose of heat. This lets the system generate a continuous series of electric pulses.

Each micro-generator can only produce about 1 milliwatt of power but an array of several thousand could produce several watts ? enough to let MEMS do plenty of useful work.

Wednesday, April 19, 2006

Shape-shifting bath

Ever felt your bath was a little too deep, too shallow, too wide or too narrow? Then you may just need the Sony Bathman - or whatever the company decides to call its latest bizarre brainwave: the shape-shifting bath.

Sony engineer Tetsujiro Kondo says in this patent application that the bathtub would have interior walls made of a strong flexible polymer, with elastic cushioning panels behind them, supported in turn by electrically controlled pressure rams. These rams give the bath's interior walls their overall shape.

A bath-mounted controller could then be used to adjust the rams and consequently the height and width of the bath's walls. Of course, there's no point making the bath narrower if it's already full, as the water would spill out. So Kondo suggests the controller could use a water level sensor to only allow the tub to adjust to shapes that can safely contain the water within it.

Tuesday, April 18, 2006

The advert enforcer

If a new idea from Philips catches on, the company may not be very popular with TV viewers. The company's labs in Eindhoven, The Netherlands, has been cooking up a way to stop people changing channels to avoid adverts or fast forwarding through ads they have recorded along with their target programme.

The secret, according to a new patent filing, is to take advantage of Multimedia Home Platform ? the technology behind interactive television in many countries around the world. MHP software now comes built into most modern digital TV receivers and recorders. It looks for digital flags buried in a broadcast, and displays messages on screen that let the viewer call up extra features, such as additional footage or information about a programme.

Philips suggests adding flags to commercial breaks to stop a viewer from changing channels until the adverts are over. The flags could also be recognised by digital video recorders, which would then disable the fast forward control while the ads are playing.

Philips' patent acknowledges that this may be "greatly resented by viewers" who could initially think their equipment has gone wrong. So it suggests the new system could throw up a warning on screen when it is enforcing advert viewing. The patent also suggests that the system could offer viewers the chance to pay a fee interactively to go back to skipping adverts. Tune in next week, when Philips may attempt to patent lead balloons.

Sunday, April 16, 2006

Microwavable packaging

The UK's Ministry of Defence spin-off company, Qinetiq, has cooked up an interesting idea - a metal wrapping that helps keeps food cold but can also be used in a microwave without sparking and damaging the machine, as ordinary metal foil does.

The secret is to make the wrapping from thin polyester and cover it with tiny squares of aluminium, the Qinetiq patent reveals. The company has found that aluminium squares 300 micrometres wide, and spaced apart by 100-micrometre tracks of clear plastic, make the perfect heatwave-frequency filter.

Microwaves at the standard frequency and wavelength ignore the grid of squares and can cook the food as normal. But normal heat is reflected, to help keep the food cool. Enough light passes through the polyester for a cook to see through the packaging and stored food will also stay fresh longer because the polyester is air-tight.

Friday, April 14, 2006

Diamond transistors

Diamonds may be a microchip's best friend, too, it seems. Scientists at the University of Chicago and Argonne National Laboratory in the US have been making electronic transistors out of pure diamond.

The transistors can withstand far higher working temperatures than conventional ones, are resistant to corrosive chemicals and would even be safe to implant in body tissue, the inventor's patent suggests. The tricky part is making sure the diamonds connect and conduct properly.

To make them, pure diamond vapour is deposited at around 900°C to form a wafer base. More diamond vapour doped with nitrogen to make it conductive, is then layered on top.

Liquid molybdenum is then selectively deposited onto the conductive diamond, to make electrical contacts, and the sandwich is topped with even more diamond, this time mixed with hydrogen, to insulate it electrically. The molybdenum spots do not bond with the hydrogen-doped diamond, so they poke through the surface and act as connector electrodes.

All-diamond chips would be way too expensive for everyday civilian use, but the researchers have found a cheaper solution that works almost as well. Instead of a pure diamond wafer base, they use conventional silicon covered with a thin layer of insulating oxide, which is then coated with a layer of conductive diamond.

Tuesday, April 11, 2006

Wing-sprouting drone

Unmanned aerial vehicles (UAVs) can fly where no pilot would dare and are hard to shoot down because they are so small. The trouble is, they also waste a lot of fuel taking off, so usually cannot stay airborne for too long.

But Daryl Elam of Arizona, US, is working on a drone that needs no fuel for take-off. It could simply be shot into the air like a shell, before sprouting wings for normal flight.

The drone's wings will be made of a tough textile, such as Kevlar, and will each contain a row of flexible hollow tubes. For launch, everything will be packed tight inside the shell. But, after reaching the right altitude, the shell will open a couple of side flaps to expose the folded wings and a pyrotechnic gas generator ? similar to an airbag inflator ? will blasts gas under pressure into the wing's tubes.

As the tubes inflate, they will expand and take on the taught shape of aerodynamic wings. The shell casing then becomes the UAV's fuselage, the wings provide lift and an onboard motor provides thrust.

The inventor reckons that, with careful packing, the stowed wings could be as small as one-thirty-fifth of their final in-flight volume.

Thursday, April 06, 2006

Tuning for oil

Wealthy oil companies are always looking for ways to save money and time, and this simple invention for finding underground oil reserves may help them do both.

The usual practice is to take fluid samples from the ground and wait several weeks for lab analysis to confirm the presence of H2S (hydrogen sulphide) and CO2 (carbon dioxide), which signals a likely oil strike. The new idea, from oil company Baker Hughes ? part of the Howard Hughes empire ? is to make compounds near oil reserves literally sing out. Or, more accurately, sing out of tune.

A vacuum cylinder, sealed with a semi-permeable membrane of silicone rubber, would be lowered down into a shaft. Gases should diffuse into the chamber and settle on a pair of gently vibrating "tuning forks", one coated with a thin layer of silver, which absorbs H2S, and the other with a layer of sodium oxide, which takes up CO2.

As the fork's surfaces absorb the gases, they will get slightly heavier and their resonant pitch will fall in frequency. This is detected by an audio sensor which signals detection of the gases. The more the pitch falls, the higher the gas concentration and the better the chances of finding "black gold".

Tuesday, April 04, 2006

Alcoholic arm scanner

Drink drivers could find themselves subjected to roadside blood tests in future. InLight Solutions, a US company that specialises in testing blood sugar levels in diabetics without needles, has developed a similar test for measuring blood alcohol.

The company's device generates a beam of infrared (IR) radiation and channels this through optical fibres into a cradle designed to attach to a forearm. When a suspect?s arm is placed in the cradle, the infrared light penetrates to a depth of 5 millimetres and the reflected light is picked up by a bunch of IR sensors. The beam is constantly moved over the skin to avoid burning it.

The reflected beam is combined with the original one to create an interference pattern. This will change depending on the amount infrared absorbed, which will depend on levels of alcohol in the blood. To calibrate the device, the inventors took 1500 measurements from 133 subjects (at a range of sobriety) and compared the results with both blood samples and breath tests.

The device should produce a stable infrared signal for at least two years, the company says. But, to avoid legal challenges, the patent recommends police surgeons periodically check the device for accuracy by putting a piece of gel soaked in pure alcohol into its cradle.